Although absorption via the skin is highly dependent on the physicochemical properties of the drug substance, the properties of the device also play an important role. Unfortunately, prediction of in-vivo performance from in-vitro data is often disappointing! Thus, testing in humans remains the only really reliable method for assessing formulation properties.
For more than 20 years we have repeatedly performed all relevant types of clinical trials with Transdermal Therapeutic Systems:
To meet the requirements of EU and US guidelines, SocraTec R&D has established methods and standard operating procedures which reflect the experience of many years with such trials.